Two girls and two guys; all four are standing up. The guys are fucking the girls up the ass while one of the girls has a strap-on and is screwing the other girl. All four folks are connected creating a solid wall. It's easy to transition from a London Bridge into a wall of jericho assuming one of the females has a strap-on ready to go.

My girlfriend and her best friend wanted to use the strap-on somehow while engaged in a four-some so we formed a solid wall of jericho and much fun was had.